0a8bf43567
The existing calculation of vmpressure takes into account only the ratio of reclaimed to scanned pages, but not the time spent or the difficulty in reclaiming those pages. For e.g. when there are quite a number of file pages in the system, an allocation request can be satisfied by reclaiming the file pages alone. If such a reclaim is successful, the vmpressure value will remain low irrespective of the time spent by the reclaim code to free up the file pages. With a feature like lowmemorykiller, killing a task can be faster than reclaiming the file pages alone. So if the vmpressure values reflect the reclaim difficulty level, clients can make a decision based on that, for e.g. to kill a task early. This patch monitors the number of pages scanned in the direct reclaim path and scales the vmpressure level according to that. Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org> Change-Id: I6e643d29a9a1aa0814309253a8b690ad86ec0b13
51 lines
1.6 KiB
C
51 lines
1.6 KiB
C
#ifndef __LINUX_VMPRESSURE_H
|
|
#define __LINUX_VMPRESSURE_H
|
|
|
|
#include <linux/mutex.h>
|
|
#include <linux/list.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/types.h>
|
|
#include <linux/cgroup.h>
|
|
#include <linux/eventfd.h>
|
|
|
|
struct vmpressure {
|
|
unsigned long scanned;
|
|
unsigned long reclaimed;
|
|
unsigned long stall;
|
|
/* The lock is used to keep the scanned/reclaimed above in sync. */
|
|
struct spinlock sr_lock;
|
|
|
|
/* The list of vmpressure_event structs. */
|
|
struct list_head events;
|
|
/* Have to grab the lock on events traversal or modifications. */
|
|
struct mutex events_lock;
|
|
|
|
struct work_struct work;
|
|
};
|
|
|
|
struct mem_cgroup;
|
|
|
|
extern int vmpressure_notifier_register(struct notifier_block *nb);
|
|
extern int vmpressure_notifier_unregister(struct notifier_block *nb);
|
|
extern void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
|
|
unsigned long scanned, unsigned long reclaimed);
|
|
extern void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio);
|
|
|
|
#ifdef CONFIG_MEMCG
|
|
extern void vmpressure_init(struct vmpressure *vmpr);
|
|
extern void vmpressure_cleanup(struct vmpressure *vmpr);
|
|
extern struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg);
|
|
extern struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr);
|
|
extern int vmpressure_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd,
|
|
const char *args);
|
|
extern void vmpressure_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd);
|
|
#else
|
|
static inline struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif /* CONFIG_MEMCG */
|
|
#endif /* __LINUX_VMPRESSURE_H */
|